This invention relates to tire buffing equipment, and more particularly, to an apparatus and method of reducing pollution such as smoke and the like emitted during the tire buffing stage of tire retreading.
The removing of tread material from tires is a well known procedure and is generally accomplished by first removing the old tread material and conditioning the remaining surface texture to accept the newly applied tread material. This is accomplished by abrading the periphery of the tire with an abrading member which may be in the form of a rasp having radially extending blades, barbs, or the like. The rasp is rapidly rotated and is moved into engagement with the tire to abrade, cut, rub, buff or otherwise effectively remove and/or wear off the old tread from the tire and condition the remaining surface for application of the new rubber or other material in which the new tread is formed.
In recent years tire manufactures have been using much finer grades of carbon black in tires as well as adding large quantities of oil. When removing the old tread material from these tires, the action of the rasp generates a considerable amount of friction, producing much smoke and other gaseous pollutants. In addition, particles ranging in the size from less than 100 microns to more than 1.5 centimeters in size can be emitted into atmosphere. Scorching of the tire surface caused by dull rasp blades or if the tire is insufficiently inflated or if the tire is not rigid can cause the new rubber not to properly adhere to the scorched tire surface and can result in premature tire failure.
As described in U.S. Pat. No. 3,614,973 to Jensen, it has been found that if the blades of the rasp are rotated through an atomized spray or mist of fluid, such as water, immediately ahead of their engagement with the tire then there is an advantageous cooling of the rasp. Some of the water will also be carried by the rotating rasp into the grinding area defined by the cutting or abrading action. As a result, the blades or teeth of the rasp will be effectively lubricated as they cut through the rubber tread of the tire so that friction is reduced and the temperature of the tread particles and dust is kept below a potential ignition point. The water also tends to congeal or coagulate powdery dust into larger size particles which are more efficiently handled by the exhaust or collecting system.
However, one problem with the previous methods of reducing the pollution emitted during tire buffing is that they require the use of large amounts of water while permitting smoke and fine particles to escape into the atmosphere.
Consequently, a need exists for an improved machine and method of reducing pollution such as smoke and the like emitted during tire buffing.